Hex is a strategy board game played on a hexagonal grid, theoretically of any size and several possible shapes, that belongs to the general category of "connection" games.

The game was invented by the Danish mathematician Piet Hein, who introduced it in 1942 at the Niels Bohr Institute. It was independently re-invented in 1947 by the mathematician John Nash at Princeton University. It became known in Denmark under the name Polygon...